#5 Fringe

Walter and William explain to Hans Froelich, Walter's father, how they traveled back in time from the 1970's to 1940's Nazi Germany. Expecting disbelief from Hans, he leads Bell and Bishop to a warehouse where they've been building a time machine--identical to the one Walter and William built. Hans explains that today was the first time they turned it on, so Bell figures that the original programming of the machine is what sent them to 1940's Germany. Another Nazi officer named Klaus Schulz is becoming suspicious of Bell and Bishop, but Hans covers for them saying they are defecting American scientists here to help with the project.